Cat Years and People Years

Cats don’t actually age 7 years for ever human year, as many people believe. Instead, they age rapidly during the first year, after which the process slows significantly.

How Old Is My Cat in Human Years?

The number of cat years equal to a single human year can only be estimated, though experts have a pretty good idea of the progression based on the ways in which cats mature over their lifespan. Tracie Hotchner, in The Cat Bible (2007), offers a breakdown of human and cat years for the first year of life:

1-month-old kitten = 6-month-old human baby

3-month-old kitten = 4-year-old child

6-month-old kitten = 10 human years old*

8-month-old kitten = 15-year-old human

A 1-year-old cat has reached young adulthood, the equivalent of 18 human years**

*Some experts estimate 6 months for a cat as 12 or 15 human years, given that many cats are capable of producing kittens at this age (some cats can reproduce as early as 5 months). Veterinarian Arnold Plotnick equates 6 months with 15 years, and 1 year with 24 years, and this may be more accurate given cats’ ability to become pregnant or sire kittens at 5 or 6 months of age.

**A few slow-maturing cat breeds (such as the Maine Coon) take several years to reach their full size, though they are capable of producing kittens long before full physical maturity is reached.

According to Hotchner, after the first year, approximate age equivalents are as follows:

2 = 24

4 = 35

6 = 42

8 = 50

10 = 60

12 = 70

14 = 80

16 = 84

Plotnick provides a similar conversion. Although he considers cats to be a little older at 1 year than does Hotchner, he believes that the aging process slows to approximately 4 years of aging for each single human year:

1 = 24

2 = 28

3 = 32

4 = 36

5 = 40

6 = 44

7 = 48

8 = 52

9 = 56

10 = 60

11 = 64

12 = 68

13 = 72

14 = 76

15 = 80

16 = 84

17 = 88

18 = 92

19 = 96

20 = 100

The oldest cat on record lived 38 years, though there are owners who have made unverified claims that their cats are even older. Cat breeds that tend to live the longest include the Siamese and the Manx. See How Long Do Cats Live? for information on cat longevity.